Don, recently VLSI announced some higher-speed silicon designs, though they don't seem to support the same Gigabit functionality as Vitesse (the VLSI silicon chips seem to only support the Gig MAC layer). These were done on .5 micron CMOS fabs, which sounds kinda big and suspicious to me. On the other hand, Vitesse seems to support the more complex layers for Gig--the physical layer, as it is known in networking jargon:
" The (Vitesse) VSC7135 is a single chip, fully integrated, 1.25Gb/s
transceiver featuring digital Clock and Data Recovery (CDR), on-chip
high-speed clock generation for transmission and 700 mW power
dissipation. The VSC7135 is ideally suited for the physical layer
interface requirements of the emerging Gigabit Ethernet market."
I do know that multi-gigabit designs are increasingly important--for example, I understand Ascend uses GaAs for their high-speed multi-gig stuff. It seems to me Gigabit Ethernet could use silicon for some less-complex areas, GaAs for others. However, I can't picture multi-gig designs in silicon anytime soon, no?
Dan |
